How to use the typesystem.SchemaDefinitions function in typesystem

def test_string_references():
    definitions = typesystem.SchemaDefinitions()

    class ExampleA(typesystem.Schema, definitions=definitions):
        field_on_a = typesystem.Integer()
        example_b = typesystem.Reference("ExampleB")

    class ExampleB(typesystem.Schema, definitions=definitions):
        field_on_b = typesystem.Integer()

    value = ExampleA.validate({"field_on_a": "123", "example_b": {"field_on_b": "456"}})
    assert value == ExampleA(field_on_a=123, example_b=ExampleB(field_on_b=456))

    class ExampleC(typesystem.Schema, definitions=definitions):
        field_on_c = typesystem.Integer()
        example_d = typesystem.Array(items=typesystem.Reference("ExampleD"))

    class ExampleD(typesystem.Schema, definitions=definitions):

album = Album.validate(
        {
            "title": "Double Negative",
            "release_date": "2018-09-14",
            "artist": {"name": "Low"},
        }
    )
    assert album == Album(
        title="Double Negative",
        release_date=datetime.date(2018, 9, 14),
        artist=Artist(name="Low"),
    )

    # Identical class names in alternate definitions should not clash.
    definitions = typesystem.SchemaDefinitions()

    class Album(typesystem.Schema, definitions=definitions):
        renamed_title = typesystem.String(max_length=100)
        renamed_release_date = typesystem.Date()
        renamed_artist = typesystem.Reference("Artist")

    class Artist(typesystem.Schema, definitions=definitions):
        renamed_name = typesystem.String(max_length=100)

    album = Album.validate(
        {
            "renamed_title": "Double Negative",
            "renamed_release_date": "2018-09-14",
            "renamed_artist": {"renamed_name": "Low"},
        }
    )

import typesystem
from apistar.document import Document, Field, Link, Section
from apistar.schemas.jsonschema import JSON_SCHEMA

SCHEMA_REF = typesystem.Object(
    properties={"$ref": typesystem.String(pattern="^#/components/schemas/")}
)
REQUESTBODY_REF = typesystem.Object(
    properties={"$ref": typesystem.String(pattern="^#/components/requestBodies/")}
)
RESPONSE_REF = typesystem.Object(
    properties={"$ref": typesystem.String(pattern="^#/components/responses/")}
)

definitions = typesystem.SchemaDefinitions()

OPEN_API = typesystem.Object(
    title="OpenAPI",
    properties={
        "openapi": typesystem.String(),
        "info": typesystem.Reference("Info", definitions=definitions),
        "servers": typesystem.Array(
            items=typesystem.Reference("Server", definitions=definitions)
        ),
        "paths": typesystem.Reference("Paths", definitions=definitions),
        "components": typesystem.Reference("Components", definitions=definitions),
        "security": typesystem.Array(
            items=typesystem.Reference("SecurityRequirement", definitions=definitions)
        ),
        "tags": typesystem.Array(
            items=typesystem.Reference("Tag", definitions=definitions)

def get_schema_definitions(self, data):
        definitions = typesystem.SchemaDefinitions()
        schemas = lookup(data, ["components", "schemas"], {})
        for key, value in schemas.items():
            ref = f"#/components/schemas/{key}"
            definitions[ref] = typesystem.from_json_schema(
                value, definitions=definitions
            )
        return definitions

import re
from urllib.parse import urljoin

import typesystem
from apistar.document import Document, Field, Link, Section
from apistar.schemas.jsonschema import JSON_SCHEMA

SCHEMA_REF = typesystem.Object(
    properties={"$ref": typesystem.String(pattern="^#/definitiions/")}
)
RESPONSE_REF = typesystem.Object(
    properties={"$ref": typesystem.String(pattern="^#/responses/")}
)

definitions = typesystem.SchemaDefinitions()

SWAGGER = typesystem.Object(
    title="Swagger",
    properties={
        "swagger": typesystem.String(),
        "info": typesystem.Reference("Info", definitions=definitions),
        "paths": typesystem.Reference("Paths", definitions=definitions),
        "host": typesystem.String(),
        "basePath": typesystem.String(pattern="^/"),
        "schemes": typesystem.Array(items=typesystem.Choice(choices=["http", "https", "ws", "wss"])),
        "consumes": typesystem.Array(items=typesystem.String()),
        "produces": typesystem.Array(items=typesystem.String()),
        "definitions": typesystem.Object(additional_properties=typesystem.Any()),
        "parameters": typesystem.Object(
            additional_properties=typesystem.Reference(
                "Parameters", definitions=definitions

import typesystem

definitions = typesystem.SchemaDefinitions()

JSON_SCHEMA = (
    typesystem.Object(
        properties={
            "$ref": typesystem.String(),
            "type": typesystem.String() | typesystem.Array(items=typesystem.String()),
            "enum": typesystem.Array(unique_items=True, min_items=1),
            "definitions": typesystem.Object(
                additional_properties=typesystem.Reference(
                    "JSONSchema", definitions=definitions
                )
            ),
            # String
            "minLength": typesystem.Integer(minimum=0),
            "maxLength": typesystem.Integer(minimum=0),
            "pattern": typesystem.String(format="regex"),

def get_schema_definitions(self, data):
        definitions = typesystem.SchemaDefinitions()
        schemas = lookup(data, ["components", "schemas"], {})
        for key, value in schemas.items():
            ref = f"#/components/schemas/{key}"
            definitions[ref] = typesystem.from_json_schema(
                value, definitions=definitions
            )
        return definitions